Improved shield for tunhbllsho



iintd tatct Leafs' Pawn.: No. 91,071, 'dated .fum s, 1869.

DPROVED SHIELD POR TUNNBLLING.

The Schedule referred to tu than Letten Patent und t paxtofxhnnme.

To all whom tima/y concern:-

Be it known that I, A. ELY BEACH, of Stratford, in the county of Fairfield, and State of Connecticut, have vinvented a' new and improved Shield for Excavating and Tunnelling; and I do hereby declare that the following is a-full, clear, and exact description thereof', which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of this specilication.

Figure 1 is a pelspeetive view of my improvement,

showing its use in connection with the building of an underground tunnel.

Figure 2 is a side sectional view ofthe same. Figure 3, an elevation of the rear end of the shield. Figure 4, a sectional elevation of a portion of the shield and one of the binding-rods'. Figure 5, a sectional elevation of a portion of the shield and one of the` pushing-devices by which the Y shield is moved.

Similar letters of refereuceindicate corresponding parts.

, The shield consists of a. cylinder, A, within which the workmen are protected while they excavate the earth in front of the shield. The latter is advanced as fast as the earth is excavated, by means of any suitable pushing-device, such as hydraulic jacks, or screws B, arranged to operate between the shield and the tunnel, the shield is pushed forward.

The shield-A may be composed of wood, metal, or

.other suitable material, of one or more pieces, andy into a recess in the face of a protecting-ring, c, of

iron. `The staves a areciamped between the ring and shoe, by means' of strong `longitudinal screw-bolts d, which extend from theshoeb through the sta-ves to ring b, where the bolts ,are tightened by means of nuts. A (See lg.'4.) l

The pushing-devices, which in the present example consist of screwslare arranged at suitable distances 'apart upon the ring c, through which they pass into yrecesses in the staves, nuts or female screws being located in or upon the ring. Y

The pushing-devices B can be thus withdrawn into the shield, by which they are supported ready for use, but out of the way until wanted.

, Instead lof working the screws singly, they may be all worked simultaneously, by means of. a suitablyarranged wheel, operated by power.

When desired, the pushingfdevices may consist of atter being constructed as' fast as the' hydraulic jacks, which may occupy the places upon the shield of the'screws, and the said jackslike the screws, may be arranged to withdraw into the shield.

Each jack may have au independent pump and liquid-reservoir, so as to be worked independently, or,

if preferable, all thejacks may be connected by sepa.- rate pipes, or -by a common pipe with a single pump .and reservoir, in such a manner that all the jacks .may be operated simultaneously by'one pump.

A stop-valve is to be so arranged, in connection with each of the jacks, that any one of them can be shut od, at the will of the operator,`from'the pump.

The pressure to direct and drive the shield can thus be conveniently regulated.

More than onepump may be employed if desired, and the pump or pumps may be arranged upon the shield, o'r, if preferred, away fromv the.` shield, with suitable conducting-pipes .extending to the jacks.

The pushing-devices areto be so arranged or attached to the shield that they will be carried upon and supported by it. A

The rear endl ofthe shield Ais provided with a thin hood, O, preferably of sheet-steel, the object of which is to prevent the caving of the earth at the rear of the shield when the latter is advanced while the tunnel is being constructed.

In operating the shield, the rear part of the hood O is intended to rest upon the exterior of the tunnel, which is built up within the hood. The latter is made in sections, the ends of whichl are riveted' together, and

the hood is secured to the shield by means of bolts,

which pass through the staves to the interior of the Shield.

In case it becomes necessary to remove the hood, or

out the section-rivets.

The shield itself can readily he taken apart byvunf screwing the nuts of thescrew-bolts d, when the shoe,

ring, and staves may be readily separated.

In soils where an, additional protectionr against caving is required, I provide the frontpart of the' shield with'av series of sliding. staves, D, so constructed and arranged that they may be driven forward"fron1 within the tube into the soil.

In the present example, 'the sliding staves D are made with double arms, forked in form, 'one' arm resting on the exterior of the shield, the other arm 'fitting upon the interior, the inner arm being slotted and guided by stops e e, as shown. o

The 'front ends of the staves D are bevelled, so as to "present a cutting-edge to the soil. They may also-be pointed.. v

The sliding staves are intended to be arranged side. by side, and to encircle the front portion of the shield; but they may he made of any suitable length, aud'any suitable number of theln may be'employed. f The use of the sliding staves will be found especially advantageous when stones are encountered, ztsthe staves may be pushed forward, by the application -of force to their inner arms, and they may thus be driven and fitted against the inequalities of the stone, so as to afford protection to the Workmen while cutting or drilling the stone from the interior of the shield.

y do not confine myself 4to the use of sliding stwes, of' the particular 'form herein shown; nor do I limit myself to the form of any of the parts herein described, as they may be severally altered in many ways without departing from my invention. v

What I claim as new, and desire to secure by Let,-

` ters Patent, is-` l. The shield A, made and operating substantially as herein shown and described. A `2. The arrangement of the pushing-devices to'wth- -draw into the shield, as herein shown and described.

6. Providing the shield with sliding Steves, substautially as :md for the purposes herein shown and de scribed.

7. The arrangement of the pushing-devices, so that they will'be carried by and supported upon the shield, substantially as and for the purposes herein described.

' A. ELY BE ACH.

Witnesses:

FRANK BLooKLEY, FRANCIS MCABDLE. 

